Pass 15

In order to obtain objective indicators related to the severity of MS, sample size estimation for Pearson correlation analyses were performed using PASS 15 (NCSS Statistical Software, USA), with a threshold of p = 0.05, a power of 0.9, and a predicted correlation coefficient between 0.4 and 0.6, yielding a sample size N between 24 and 61. The trial recruited 51 male participants (mean age, 24.54 ± 3.19 years; mean height 175.25 ± 5.80 cm; mean weight, 71.54 ± 2.89 kg), and none of them had a history of epilepsy, increased intracranial pressure, vertigo, cerebrovascular accident, severe mental illness, and drug abuse. None of the participants took any medications or alcoholic beverages within 48 h, and they participated in the experiment 1 h after eating. Physical examination of each participant showed no signs of external otitis, tympanic membrane perforation, or spontaneous nystagmus. Their naked or corrected visual acuity were 1.0 at least and color vision were normal. The study was approved by the Ethics Committee of the First Affiliated Hospital of the Fourth Military Medical University (number: KY-20202054-F-2). Each participant signed an informed consent form and volunteered to participate.

The sample size was calculated to determine how many participants would be needed to detect a risk reduction from 6% by chlorhexidine-alcohol to 4% by povidone-iodine. We estimated the perineal infection rate as 6% for povidone-iodine, according to our retrospective database. To have 80% power, a type 1 error of 0.05, and a ratio of 1:1 between chlorhexidine-alcohol and 4% by povidone-iodine, a total of 3726 subjects will need to be randomized. To accommodate a 10% dropout rate, 4140 subjects will be enrolled (2070 chlorhexidine-alcohol, 2070 povidone-iodine). The sample size was calculated (PASS 15 (NCSS Statistical Software, USA)) based on the primary endpoint of the study.

The sample size was calculated by PASS 15.0 (NCSS Statistical Software, Kaysville, Utah). We estimated that a sample of 40 participants in each group was needed for a statistically significant odds ratio (OR) of 2, with an alpha of 0.05 and a beta of 0.2. Based on a 20% drop-out rate, at least 50 cases needed to be included in each group (a total of 100 cases).
All data analyses were conducted using SPSS 21 software (IBM Corp. Armonk, NY, USA). Measurement data were expressed as mean ± SD and analyzed by the t-test. Enumeration data were expressed as [n (%)] and analyzed using the χ² test. A P < 0.05 was indicative of a statistically significant difference.

The normal approximation method in PASS 15.0 (NCSS Statistical Software, Kaysville, Utah) was adopted for the calculation of sample size. A preliminary analysis was conducted to the data at the level of bilateral test α = 0.0500. Assuming that the two-year survival rates of the Obs and Con groups were 74% and 50%, respectively, and 80% power was required, the sample size of each group was at least 61 cases, with 122 cases in total. Based on 20% loss rate, at least 77 cases should be included in each group, a total of 154 cases.
Statistical data were analyzed using SPSS 22.0 software package (IBM Corp., Armonk, NY, USA); GraphPad Prism 6.0 (GraphPad Software, La Jolla California USA) was used to visualize the data. Comparisons of count data [N (%)] were conducted via the χ2 test and fisher's exact test, and intergroup and introgroup comparisons of measurement data in normal distribution (Mean ± SD) were performed by independent sample T test and paired T test, respectively. We analyzed differences between groups at all time points (before surgery, before radiotherapy, and after radiotherapy) using repeated measures analysis of variance (ANOVA) and then the Bonferroni post hoc test. Kaplan–Meier analysis was applied to overall survival. With α = 0.0500 as test standard, P < 0.0500 implies a notable difference.

The sample size was estimated using PASS 15.0 (NCSS Statistical software) with the following parameters: power of .90, alpha of .05. The hypothetical proportions of lesions with or without peritumoral abnormalities when the doses are greater than 120Gy were .75 and .05, respectively. Statistical analyses were performed using SPSS 26.0 (IBM) or GraphPad Prism 8 (GraphPad Software). The significance level was set to .05. The normality test was used to assess the normality of data and no data points were removed from the analysis. Pearson’s χ² or Fisher’s exact test was used to compare categorical data. An independent t-test was used to evaluate the significance of the difference in D90 between lesions with or without peritumoral abnormalities.